Waikīkī Beach Walkway

Public access alongshore in parts of Waikīkī is severely limited due to beach erosion, deteriorated walkways and wave run-up resulting in unsafe conditions for residents and locals that traverse this area. A proposed beach improvement project might be the catalyst to also improve the walkway as part of a broader public infrastructure plan.

The historical context of Waikīkī reveals a significantly altered landscape. What was once wetland and loʻi kalo (a submerged water-based kalo or taro farming technique similar to rice paddies) were drained through the construction of the Ala Wai Canal in the early 1920’s. This wetland drainage, along with massive coral reef and sand dredging throughout Waikīkī was followed by rapid coastal development. This had a dramatic impact on the Waikīkī environment, forever changing these unique coastal ecosystems.

Waikīkī Beach is a highly engineered urban shoreline with the modern configuration largely the result of past engineering efforts (e.g., groins, seawall, and sand fill) intended to widen the beach. 

The Waikīkī area is part of the widely recognized economic hub for the State of Hawaii and although Waikīkī is predominantly a visitor and hotel industry economic sector, the shoreline area is heavily utilized by local residents as well, serving as a critical lateral access corridor along the shore and has a demonstrated vulnerability to the impacts of sea-level rise, coastal storms, wave attack, and coastal erosion.

The Halekulani beach cell of Waikīkī Beach is in a neglected state and requires maintenance and strategic improvements to maintain and improve beach access and public safety in the area.  Due to chronic and seasonal beach erosion, the beach in this area has deflated approximate 4-5 feet, resulting in a destabilized beach system and unsafe lateral shoreline public access due to high tide wave swash.  This presents an unusual public safety hazard due to the high traffic volume for the public walkway and the unpredictable nature of tide and wave run up at the project site.

Waikīkī beach is largely defined by historic shoreline structures that create district littoral beach cells. This coastal environment is much different than many shorelines in Hawai‘i as well as those that are found in a continental setting. Waikīkī Beach is inherently unstable and has experienced chronic erosion since it was first enhanced in the early 1900s, in part due to the history of repeated human interventions to alter the shoreline, primarily through sediment placement, shoreline armoring and shoreline stabilizing structures.

Sea level rise and groundwater inundation pose a serious threat to Waikiki's infrastructure, ecosystems and economy. The U.S. Interagency Sea Level Rise Scenario Tool provides a range of sea level rise scenarios for Honolulu out to the year 2150.   ^[1]     Five different sea level rise scenarios have been developed under a multi-agency federal task force that provide both global mean and local relative SLR scenarios to 2150.   ^{[2]      [1]}    Interagency Sea Level Rise Scenario Tool;    ^[2]    Interagency Sea Level Rise Scenario Tool 

The City and County of Honolulu Climate Change Commission’s (HCCC) updated (2022) sea level rise guidance and recommendations. For planning and policy, the HCCCʻs guidance recommends using the interagency Intermediate High (5.8 ft by 2100) sea level rise scenario for all planning and design of public infrastructure projects and other projects with low tolerance for risk.    ^[1]    City & County of Honolulu Climate Change Commission (HCCC, 2022).   Updated Sea Level Rise Guidance  (July, 2022).

The public walkway along the Halekulani beach cell of Waikīkī is approximately 1000 feet in length and discontinuous. In order to transit laterally across the area there are several area where the access is across the beach. There are deteriorated beach stairs that are closed and sections that are exposed to frequent wave run up.

Lateral access to the Halekulani walkway requires scrambling around a narrow beach between waves then terminates into a crumbling walkway with hazardous conditions at high tide or when there are waves.

 A new coastal boardwalk connecting the east and west sides of the Waikiki through this deteriorated beach area would benefit locals and visitors by providing safe lateral coastal access. The boardwalk could be located in an area that is currently partially impassable and has been deemed unsafe due to damage from extreme beach erosion and coastal infrastructure failure. A new boardwalk here will serve as an important public amenity and revitalize this vital but neglected beach area. 

There is a clear need to improve the existing walkway for public safety and to prevent the further deterioration of the walkway and associated seawalls. Changing coastal conditions and beach erosion have deteriorated existing infrastructure, creating hazardous conditions for both resident and visitor pedestrians in the Waikiki region.

In areas where the walkway has not yet collapsed, the walkway is narrow, inaccessible to those who cannot use stairs, and is often overtopped by sand and crashing waves creating an extremely hazardous environment.

The need for a dedicated public access boardwalk is critical to overall improvement of this beach area.  Even if the proposed beach improvements do occur it will still restrict access to those that can transit over the sand and will not benefit those with limited mobility since the current walkway is discontinuous and requires traversing the beach in sections.

The Waikīkī community generally supports comprehensive, forward-thinking improvement public amenity projects like the proposed boardwalk.  With the combination of beach erosion and King Tides, the area is frequently flooded, particularly during high surf events, accelerating damage to back-shore infrastructure. 

We are now at a crossroads with a clear and increasingly urgent need to implement maintenance and improvements to the shoreline in order to preserve, protect and enhance this unique and highly prized natural resource.